BGS 88, Reaction to Puccinia hordei 2 (barley leaf rust), Rph2

Resistance to Puccinia anomala Rostr = Pa (2).
Resistance to Puccinia hordei Otth 2 = Pa2 (9, 15).
Resistance to Puccinia hordei A = A (8, 9).

Monofactorial incomplete dominant (2, 14).
Located in chromosome 5HS (1); not in the long arm (10); distal from the secondary constriction (1); about 3.5 cM proximal from RFLP marker CDO749 in 5H bin 04 (1).

The seedling reaction type is 0n - 1c with race 4 culture 57-19 (2); heterozygotes have reaction types ranging from 1 to 3, depending on parents. Responses will vary for homozygotes and heterozygotes when different rust cultures are tested (8).

Natural occurrence in Peruvian (CIho 935) and several other cultivars (2, 4, 6, 12, 15, 16).

Rph2.b (GSHO 1593) in Peruvian (CIho 935) (4, 12); Rph2.j in Batna (CIho 3391) (7, 12); Rph2.k in Weider (No 22, PI 39398) (2, 11, 15); Rph2.l in Juliaca (PI 39151) (3, 12); Rph2.m in Kwan (PI 39367, GSHO 1392) ( 2, 4, 12); Rph2.n in Chilean D (PI 48136) (4, 14); an allele at the Rph2 locus is present in Purple Nepal (CIho 1373), Modia (CIho 2483), Morocco (CIho 4975), Barley 305 (CIho 6015), Marco (PI 94877) (2); Austral (CIho 6358) (4, 6, 7, 12); Marocaine 079 (CIho 8334) (6); Q21861 (PI 584766), TR306 (1, 13); accessions with a second Rph gene besides the Rph2 allele include Carre 180 (CIho 3390), CIho 14077 (12); Ricardo (PI 45492) (2, 14, 16); Ariana (CIho 14081) (11, 12, 16); Quinn (PI 39401) (8, 9); Bolivia (PI 36360) (2, 8, 9); Reka 1 (CIho 5051) (4, 6, 7, 12); tentative Rph2 allele symbols are Rph2.q in Quinn, Rph2.r in Bolivia (GSHO 1598), Rph2.s in Ricardo, Rph2.t in Reka 1 (GSHO 1594), and Rph2.u in Ariana based on differential reactions and different cultivar origins (5, 8, 9, 12); Rph2.y from HJ198*3/HS2310 (PI 531841, GSHO 1595) (3).

Rph2.b in Peruvian (GSHO 1593); Rph2.b from Peruvian in Bowman (PI 483237)*3 (GSHO 2320, PI 643151, BW737, NGB 22443); Rph2.j from Batna in Bowman*6 (PI 643165, BW738, NGB22444); Rph2.l from Juliaca in Bowman*4 (BW739, NGB 22445); Rph2.r from Bolivia in Bowman*5 (BW742, NGB 22448); Rph2.t from Rika 1 in Bowman*8 (GSHO 2321, PI 643167, BW 743, NGB 22449); Rph2.y from PI 531841 in Bowman*5 (PI 643166, BW744, NGB 22450).

1. Borovkova, I.G., Y. Jin, B.J. Steffenson, A. Kilian, T.K. Blake, and A. Kleinhofs. 1997. Identification and mapping of a leaf rust resistance gene in the barley line Q21861. Genome 40:236-241.
2. Henderson, M.T. 1945. Studies of the sources of resistance and inheritance of reaction to leaf rust, Puccinia anomala Rostr., in barley. Ph.D. Thesis. Univ. of Minnesota, St. Paul.
3. Jin, Y., G.H. Cui, B.J. Steffenson, and J.D. Franckowiak. 1996. New leaf rust resistance genes in barley and their allelic and linkage relationships with other Rph genes. Phytopathology 86:887-890.
4. Levine, M.N., and W.J. Cherewick. 1952. Studies on dwarf leaf rust of barley. U.S. Dept. Agr. Tech. Bull.1056. 17p.
5. Moseman, J.G., and L.W. Greeley. 1965. New physiological strains of Puccinia hordei among physiological races identified in the United States from 1959 through 1964. Plant Dis. Rep. 49:575-578.

6. Moseman, J.G., and C.W. Roane. 1959. Physiologic races of barley leaf rust (Puccinia hordei) isolated in the United States from 1952 to 1958. Plant Dis. Rep. 43:1000-1003.
7. Reinhold, M., and E.L. Sharp. 1982. Virulence types of Puccinia hordei from North America, North Africa and the Middle East. Plant. Dis. 66:1009-1011.
8. Roane, C.W. 1962. Inheritance of reaction to Puccinia hordei in barley. I. Genes for resistance among North American race differentiating varieties. Phytopathology 52:1288-1295.
9. Roane, C.W., and T.M. Starling. 1967. Inheritance of reaction to Puccinia hordei in barley. II. Gene symbols for loci in different cultivars. Phytopathology 57:66-68.
10. Roane, C.W., and T.M. Starling. 1989. Linkage studies with genes conditioning leaf rust reaction in barley. Barley Newsl. 33:190-192.
11. Sharp, E.L., and M. Reinhold. 1982. Resistance gene sources to Puccinia hordei in barley. Plant Dis. 66:1012-1013.
12. Starling, T.M. 1955. Sources, inheritance, and linkage relationships of resistance to race 4 of leaf rust (Puccinia hordei Otth), race 9 of powdery mildew (Erysiphe graminis hordei El. Marchal), and certain agronomic characters in barley. Iowa State Coll. J. Sci. 30:438-439.
13. Steffenson, B.J., and Y. Jin. 1997. A multi-allelic series at the Rph2 locus for leaf rust resistance in barley. Cereal Rusts Powdery Mildews Bull. (in press).
14. Tan, B.H. 1977. Evaluation host differentials of Puccinia hordei. Cereal Rust Bull. 5:17-23.
15. Watson, I.A., and F.C. Butler. 1947. Resistance to barley leaf rust (Puccinia anomala Rostr.). Linnean Soc. New South Wales, Proc. 72:379-386.
16. Zloten, R.R. 1952. The inheritance of reaction to leaf rust in barley. M.S. Thesis. Univ. of Manitoba, Winnipeg.

Y. Jin and J.D. Franckowiak. 1997. Barley Genet. Newsl. 26:126-127.

J.D. Franckowiak. 2007. Barley Genet. Newsl. 37:212-213.